Biomedical subjects

L S Jensen

Publications and source records attributed to L S Jensen.

At least 19 recordsLinked to original sources

PubMed1992

Postoperative infection and natural killer cell function following blood transfusion in patients undergoing elective colorectal surgery.

The frequency of infection in 197 patients undergoing elective colorectal surgery and having either no blood transfusion, transfusion with whole blood, or filtered blood free from leucocytes and platelets was investigated in a prospective randomized trial. Natural killer cell function was measured before operation and 3, 7 and 30 days after surgery in 60 consecutive patients. Of the patients 104 required blood transfusion; 48 received filtered blood and 56 underwent whole blood transfusion. Postoperative infections developed in 13 patients transfused with whole blood (23 per cent, 95 per cent confidence interval 13-32 per cent), in one patient transfused with blood free from leucocytes and platelets (2 per cent, 95 per cent confidence interval 0.05-11 per cent) and in two non-transfused patients (2 per cent, 95 per cent confidence interval 0.3-8 per cent) (P less than 0.01). Natural killer cell function was significantly (P less than 0.001) impaired up to 30 days after surgery in patients transfused with whole blood. These data provide a strong case against the use of whole blood transfusion in patients undergoing elective colorectal surgery.

Adult↗

PubMed1992

Cholesterol concentration of egg yolk and blood plasma and performance of laying hens as influenced by dietary alpha-ketoisocaproic acid.

Experiments were conducted to determine the effect of supplemental alpha-ketoisocaproic acid (KIC) or Leu on layer performance and plasma and egg cholesterol levels. In the first experiment, 0, .09, or .27% KIC and .09 or .27% Leu were fed to 62-wk-old laying hens. In a second experiment, the same levels plus another level of .54% KIC and .54% Leu were fed to 32-wk-old hens for an 8-wk period. The basal diet or the basal diet supplemented with .27% KIC or .27% Leu were continued for 20 wk to determine the long-term effects of these supplements. In a third experiment, hens were fed 0, .1, .2, or .4% KIC for 8 wk. The addition of KIC and Leu to the hen diets did not affect percentage egg production, egg weight, shell thickness, or Haugh units. In Experiment 1, .27% KIC and .09% Leu significantly increased BW gain. Neither KIC or Leu significantly affected BW gain in Experiment 2 when measured at 8 or 28 wk. In the third experiment, diets supplemented with KIC increased significantly BW gain. In Experiment 1, .09% KIC and .09% Leu significantly reduced egg cholesterol at 4 wk. After 8 wk, .27% KIC reduced egg cholesterol significantly below the controls. No effect on plasma or egg cholesterol was observed in Experiments 2 and 3.

Animal Feed↗

PubMed1992

Research note: putrescine effects on performance of male broiler chicks fed low-protein diets supplemented with essential amino acids.

The purpose of the present study was to determine whether a polyamine deficiency could account for the reduced performance of broiler chicks fed a low-protein diet supplemented with several synthetic amino acids in comparison with those fed a more conventional CP concentration. Male broiler chicks were fed equicaloric diets calculated to contain 23, 20, or 17% CP. Each diet was supplemented with 0, .05, or .10% putrescine in a 3 x 3 factorial arrangement of treatments. Body weight gain of chicks fed the 17% CP diet was significantly (P less than .05) less than that of those fed the higher protein diets and feed conversion ratio significantly increased as the CP concentration decreased. Adding putrescine failed to significantly affect any of the parameters within each CP concentration. A deficiency of polyamines does not appear to explain the lower performance of broiler chicks fed low CP diets with added synthetic amino acids.

Amino Acids, Essential↗

PubMed1992

Influence of dietary taurine on performance and fat retention in broilers and turkey poults fed varying levels of fat.

Taurine, an amino acid synthesized from Met, primarily functions in bile acid conjugation. Four experiments were conducted to determine whether Tau supplementation of broiler cockerels and female turkey poults to 3 wk of age would influence performance and fat retention at different levels of dietary fat. In these experiments, Tau was added at 0 or .8% to a corn and soybean meal basal diet with dietary poultry fat added at 0, 5, or 10%. Taurine did not affect BW gain of broiler cockerels; however, in one experiment feed efficiency was improved (P less than .01) during the 1st wk and fat retention was improved (P less than .06) at 7 days of age. In experiments with turkey poults, dietary Tau did not affect weight gain but improved feed efficiency (P less than .01) during the 1st wk and decreased overall feed efficiency (P less than .01) in one experiment. Improvement of fat retention by Tau at 14 days was significant (P less than .02) in one experiment and approached significance (P less than .07) in the other experiment. Fat supplementation of both the broiler and turkey diets significantly (P less than .05) improved weight gain, feed efficiency, and fat retention. Supplementary Tau appears to have little effect on performance of broilers and turkeys.

Animal Feed↗

PubMed1992

Growth and tissue lipid deposition of broilers fed alpha-ketoisocaproic acid.

Dietary alpha-ketoisocaproic acid (KIC) was studied for effects on growth, feed efficiency, tissue cholesterol (TC) content, and immune response to a Newcastle disease virus (NDV) vaccination in broilers. In two experiments, broiler chicks were fed diets supplemented with graded levels of KIC to .54% of the diet. Feed efficiency, fat deposition, BW gain, and plasma cholesterol levels were determined at 3 wk. In a third experiment, broilers were fed diets supplemented with 0, .1, .2, and .4% KIC throughout the starter (0 to 3 wk), grower (3 to 6 wk), and finisher (6 to 7 wk) periods. Abdominal fat and plasma and breast TC were measured at 7 wk. In Experiment 4, levels of KIC to .6% were fed to broilers to determine TC content and to measure the immune response to NDV vaccination. Feed efficiency, BW gain, and percentage abdominal fat were not affected by KIC in any of the broiler experiments. The addition of KIC to broiler diets resulted in a significant reduction in breast (Pectoralis major) TC. Biceps (Biceps femoralis) TC, adductor (Pubo-ishio-femoralis) TC, and plasma cholesterol content was not affected by KIC. Geometric mean titers to NDV were not improved by KIC. The data indicate that KIC has no effect on growth or abdominal fat deposition, but may have a role in TC homeostasis.

Adipose Tissue↗

PubMed1991

A time-dependent study of passive esophageal wall properties and collagen content in rabbits with esophageal varices.

The passive biomechanical wall properties of the esophagus were studied in rabbits with esophageal varices and controls using a four-electrode impedance technique. Stepwise pressure inflation and deflation was done for analysis of esophageal cross-sectional area, compliance, and hysteresis monthly during six months. At sacrifice, the esophageal collagen content was determined. A small but statistically insignificant increase in compliance was observed during the six-month observation period in both groups. No differences were observed between the groups (P greater than 0.3). No change in hysteresis was observed in either group. The group with esophageal varices had significantly higher collagen content in the distal esophagus when compared to controls (P less than 0.05). No difference was demonstrated in the proximal part. No correlation was demonstrated between the collagen content and esophageal compliance. The study demonstrated that the method allows measurement of luminal cross-sectional area and tissue elasticity. No relationship was found, however, between the collagen content and compliance of the rabbit esophagus.

Animals↗

PubMed1991

Influence of orotic acid on performance, liver lipid content, and egg cholesterol level of laying hens.

Three experiments were conducted to determine the effects of dietary orotic acid (OA) on laying hen performance, liver lipid content, and plasma and egg cholesterol levels. Laying hens were fed a basal diet supplemented with 0, .5, 1.0, and 2.0% OA for 8 wk. Performance of the hens and cholesterol levels were measured at biweekly intervals. In all three experiments, OA decreased (P less than .05) BW in a linear manner. In two experiments, OA caused a linear decrease in total liver lipid (P less than .05), and in a third experiment OA resulted in a quadratic effect (P less than .01) on liver lipid content. There were no effects observed by OA supplementation on egg weight, yolk weight, percentage yolk, or egg production. Orotic acid failed to influence egg cholesterol content in any of the biweekly measurements of the three experiments. In two experiments, total plasma cholesterol content was not influenced by OA supplementation. Orotic acid significantly reduced (P less than .05) free and total plasma cholesterol in a third experiment when measured at Weeks 4, 6, and 8 of the experiment. The data indicate that OA is an ineffective dietary supplement for reducing egg cholesterol levels in laying hens.

Animals↗

PubMed1991

Effect of age of hen, egg weight, and sex on chick performance and lipid retention.

Experiments were conducted to determine whether age of hen, weight of the egg, and sex of the chick affected fat retention and growth of the broiler chick. Chicks were fed a corn and soybean meal diet containing 5% supplemental poultry fat. In the first study, eggs from two ages of hens were compared (30 and 52 wk) with six egg weight classes per age. The second experiment consisted of three hen ages (31, 37, and 47 wk) with three egg weight classes per age. The results indicated that as hen age and egg weight increased, BW gain of the chicks increased but feed efficiency and fat retention were not affected. Females had improved fat retention when compared with males. When analyzed within each egg weight class, there was no age effect on fat retention, BW gain, or feed efficiency.

Age Factors↗

PubMed1991

Influence of protein concentration, amino acid supplementation, and daily time to access to high- or low-protein diets on egg weight and components in laying hens.

Feeding a 13% CP diet based on corn and soybean meal and supplemented with methionine to laying hens results in reduced egg weight in comparison with hens fed a corn and soybean meal methionine-supplemented diet containing 16% CP. An experiment was conducted to determine whether the egg weight reduction could be eliminated by supplementing the low-protein diet with additional lysine, methionine, and tryptophan or by adding glycine and glutamic acid to increase the amino nitrogen to a level equivalent to 16% CP. The influence of the dietary treatments on the weight of the major egg components was also determined. In a second experiment, the influence of time of day of feeding the 13 or 16% CP diets on egg weight and egg components was determined. Adding additional amino nitrogen in the form of glycine and glutamic acid or increasing the levels of lysine, methionine, or tryptophan individually or in combination failed to prevent the depression in egg weight of hens fed the lower protein diet. Measurement of egg components demonstrated that the reduction in egg weight was primarily associated with a reduction in albumen content of the egg. Feeding a high-protein diet from 1400 to 0800 h and a low-protein diet from 0800 to 1400 h resulted in egg weight equivalent to that from hens continuously fed the high-protein diet. The lower weight of the albumen in eggs from hens fed a 13% CP diet may be due to a lower availability of amino acids for protein synthesis during the 3- to 4-h period when the ovum is in the magnum.

Amino Acids↗

PubMed1990

Comparison of one dose versus three doses of prophylactic antibiotics, and the influence of blood transfusion, on infectious complications in acute and elective colorectal surgery.

In a randomized prospective controlled trial involving 311 patients undergoing acute or elective colorectal surgery, the efficacy and safety of two different single dose and one triple dose regimen of antibiotic prophylaxis, as well as the influence of blood transfusion on postoperative infectious complications, were studied. Postoperative infectious complications occurred in a total of 59 patients (19.0 per cent). There were no major differences between the three treatment groups. Thirty-four patients (10.9 per cent) developed abdominal wound infection, 17 patients (5.5 per cent) intra-abdominal abscess and 16 patients (5.1 per cent) anastomotic leakage. Of 202 patients (65.0 per cent) requiring blood transfusion during hospitalization 57 (28.2 per cent; 95 per cent confidence limits of 23-36 per cent) developed infectious complications, whereas two non-transfused patients (1.8 per cent; 95 per cent confidence limits of 0.2 to 6 per cent; P less than 0.001) developed infectious complications. It is concluded that one single dose of antibiotic prophylaxis in acute and elective colorectal surgery is as protective as a triple dose regimen. The development of infectious complications despite antibiotic prophylaxis is strongly related to blood transfusion.

Adolescent↗

PubMed1990

Propranolol may prevent recurrence of oesophageal varices after obliteration by endoscopic sclerotherapy.

In 29 patients admitted with their first bleeding episode from oesophageal varices the varices were obliterated within 6 months by treatment with serial endoscopic sclerotherapy and propranolol or with sclerotherapy only. The patients were checked regularly during 18 months after the varices had been obliterated. Variceal recurrence was found in 11 patients (73%; 95% confidence limits, 45-92%) treated with sclerotherapy only and in 2 patients (15%; 95% confidence limits, 2-43%; p less than 0.01) treated with sclerotherapy and propranolol. In nine patients (69%) with recurrence significant variceal bleeding occurred. All recurrences were observed within 12 months after the initial obliteration. Variceal recurrence occurred in 3 Child A patients and in 10 Child B or C patients. All bleeding occurred in Child B or C patients. It is concluded that obliteration of oesophageal varices by endoscopic sclerotherapy and propranolol may be more effective in the long-term control of variceal recurrence than treatment with sclerotherapy only.

Adult↗

PubMed1990

Effectiveness of ascorbic acid and chromium in counteracting the negative effects of dietary vanadium on interior egg quality.

Four experiments were conducted to investigate further the effects of V on hen performance and egg quality as well as on the ability of ascorbic acid and Cr to counteract the deleterious effects of V on interior egg quality. At 10 ppm, added V significantly reduced albumin quality as measured by Haugh units; and at 30 ppm and 100 ppm, respectively, significantly reduced rate of lay and feed consumption and also increased body weight loss. As measured by shell breaking strength or shell thickness, shell quality was not affected significantly by V (added to a maximum of 100 ppm). Ascorbic acid (100 to 5,000 ppm) effectively protected the hens from the reduction in albumen quality resulting from the addition of 10 ppm of V to the basal diet. Hen performance and egg quality were not significantly affected by adding 10 or 50 ppm of Cr to a diet with 10 ppm of added V, nor by adding 30 or 150 ppm of Cr to a diet with 30 ppm of added V. The added Cr failed to counteract the depressing effects of V on the Haugh units recorded, regardless of the composition of the basal diet.

Analysis of Variance↗

PubMed1990

The requirement for sulfur amino acid by laying hens as influenced by the protein concentration.

Two experiments were conducted with White Leghorn laying hens to determine the influence of the dietary CP concentration on the requirement for TSAA. Supplements of 0, .05, .1, or .15% of DL-methionine (Experiment 1) and 0, .025, .05, .075, .1, or .125% of DL-methionine (Experiment 2) were each added to corn-soybean meal diet with 13, 16, or 19% CP. Experiment 1 was conducted for 4 wk (four groups of 10 hens, 32 wk of age per treatment). Experiment 2 was conducted for 5 wk (three groups of 9 hens, 59 wk of age per treatment). Methionine supplementation significantly improved egg production in Experiment 2, and in Experiment 1, the increase in egg production approached significance (P = .077). Egg production was highly significantly improved by increasing the protein level in both experiments. Egg weight was increased by methionine supplementation at all protein levels. For Experiments 1 and 2, respectively, the estimated requirement for TSAA in order to achieve maximum egg mass (grams of egg per day) was .61 and .54% for 13% CP, .61 and .65% for 16% CP, and .68 and .73% for 19% CP. The methionine requirement for maximum egg mass in Experiment 2 was .29%, .36 and .41% for 13, 16, and 19% CP, respectively, but was not improved in Experiment 1 by increasing the concentration of protein. Feed per gram of egg, but not feed per dozen eggs, was improved by methionine supplementation at all CP levels. Body weight gain generally increased along with the CP levels and with methionine supplementation, but the methionine requirement for maximum body weight did not appear to increase along with the increase in protein concentration. The results of the present study show that the concentration of dietary protein should be considered when determining the requirement of laying hens for TSAA.

Amino Acids, Sulfur↗

PubMed1990

Effect of feeding isoniazid and cimetidine on growth and bone development in male broiler chicks.

Because previous studies indicated that cimetidine (CIMET) and isoniazid (ISON) may inhibit vitamin D metabolism in both rats and humans, experiments were conducted to evaluate the influence of these drugs on growth and bone development in male broiler chicks. Chicks were fed a corn and soybean meal basal diet containing various levels of the drugs for 21 days. Body weight gain (BWG), feed consumption per bird (FB), tibia ash (TA), tibia breaking force (TBF), and plasma calcium levels were measured. In birds fed a diet supplemented with 1,100 ICU D3/kg, CIMET at up to 300 ppm resulted in a significant linear decrease in TA as the drug level increased. Birds fed ISON up to 405 ppm had inconsistent responses in TA and TBF. Body weight gain was only depressed with the highest level of ISON (405 ppm). The effects of feeding 0, 150, or 300 ppm CIMET were also investigated when chicks were fed 200 or 1,000 ICU per kg vitamin D3. The interaction between vitamin D3 and CIMET was significant for BWG, FCB, TA, and TBF. These were significantly reduced as the CIMET level increased for birds fed the low vitamin D3 diet but were not significantly affected when fed the high D3 diet. In another study in which chicks were fed a diet with 1,100 ICU vitamin D3, lowering the dietary Ca, or P, or both did not result in any effect of CIMET on the chicks. The results indicate that CIMET possibly interferes with normal bone formation in chicks by altering vitamin D3 metabolism.

Animals↗

PubMed1990

Dietary and monensin effects on activity of hepatic microsomal mixed function oxidase system in chickens.

Four experiments were conducted to investigate if the degree of activation of the microsomal mixed-function oxidase (MFO) system was related to the degree of growth depression associated with the addition of monensin to the diet. The experiments were conducted with broiler chicks in battery brooders in which the chicks were fed diets of various composition and containing monensin at 0 to 160 ppm. In all experiments, the activity of the MFO system was estimated by the change in the content of cytochrome P-450 in the hepatic microsomes. Activities of some microsomal enzymes were also measured in some of the experiments. Feeding a diet with 24% protein containing fish meal, alfalfa meal, and torula yeast significantly increased the activity of the MFO system in comparison with feeding an isonitrogenous and isoenergetic corn and soybean diet, but there was no difference between the diets in the toxicity of monensin as measured by growth rate. Supplementing a 16% protein but not a 24% protein diet with monensin significantly reduced growth rate. In none of the four experiments was there a statistically significant change in the hepatic content of cytochrome P-450 as a result of feeding monensin. Thus, variation in the magnitude of growth depression caused by monensin in diets of different protein concentration or ingredient composition does not appear to be explained on the relative degree of the activation of the MFO system.

Animal Feed↗

PubMed1990

Arginine requirement of starting broiler chicks.

Three experiments were conducted to estimate the arginine requirement of male broiler chicks from 0 to 3 wk of age. The experiments were conducted in battery brooders with wires floors, and the birds received water and feed ad libitum. In the first experiment, chicks were fed a diet based on corn, soybean meal, casein, and corn-gluten meal containing 3,200 kcal ME per kg and either 20 or 23% crude protein. Regression analysis indicated an arginine requirement of 1.22% for maximum growth rate and feed efficiency with the 20% protein diet. For chicks fed the 23% protein diet, neither growth rate nor feed efficiency was significantly different among the diets containing arginine ranging from 1.13 to 1.43%. In the second experiment, a basal diet was used containing 17.5% casein and 22.5% protein with arginine ranging from 1.03 to 1.43%. An arginine requirement of 1.18% for maximum body weight gain was estimated by regression analysis, but no significant response to arginine above the basal level was observed for feed efficiency. Performance of chicks fed the basal diet was somewhat reduced because of a difficulty with adherence of feed to the beaks. In a third experiment, three basal diets containing 21, 22, or 23% protein were formulated from practical ingredients without use of casein. The requirement for maximum growth rate and feed efficiency was estimated to be 1.24 to 1.28% for the three diets. The results of these investigations indicate that the arginine requirement for starting chicks suggested by the National Research Council in 1984 of 1.44% in diets containing 3,200 kcal ME per kg is too high for practical diets. The data presented here support an arginine requirement of 1.25%.

Age Factors↗

PubMed1990

Effect of cimetidine on eggshell quality and plasma 25-hydroxycholecalciferol in laying hens.

Experiments were conducted to investigate the effect of feeding cimetidine (CIMET), ranging from 0 to 750 mg/kg, on vitamin D3 metabolism and eggshell calcification in laying hens fed two levels of vitamin D3 (500 and 2,000 ICU/kg). Final BW and feed intake were not significantly affected by either CIMET or vitamin D3 level. Feeding 500 and 750 mg of CIMET significantly decreased total egg production in hens fed either level of vitamin D3, but no differences were observed at lower CIMET levels. Tibia ash decreased significantly in hens fed 150 to 750 mg of CIMET, regardless of the vitamin D3 level. Plasma Ca and inorganic P concentrations were decreased in hens fed high CIMET levels (500 and 750 mg/kg) at Week 2, but no differences were observed at Week 4. Feeding CIMET (500 and 750 mg/kg) significantly decreased plasma 25-hydroxycholecalciferol (25-OHD3) levels at Week 2 in hens fed both vitamin D3 diets but not at Week 4. Eggshell breaking force, shell thickness, and percentage shell weight were decreased significantly by CIMET in all experiments; however, in one experiment, shell quality recovered by Week 8. These results suggest that the CIMET-induced reduction in bone mineralization, eggshell quality, and plasma 25-OHD3 levels could be due to interference of CIMET with vitamin D3 metabolism in vitamin D3-replete laying hens. Shell quality decreased in CIMET-treated hens fed the higher vitamin D diet even though 250-HD3 plasma levels were three times higher than in hens fed the lower vitamin D diet, suggesting that CIMET affected shell quality through some mechanism other than inhibition of 250-HD3 synthesis.

Animal Feed↗

PubMed1990

Broiler chick response to low protein diets supplemented with synthetic amino acids.

Performance of broiler chicks fed low protein diets supplemented with several essential amino acids (EAA) is generally inferior to that of birds fed a higher protein diet composed primarily of intact protein. Two experiments were conducted to determine whether lowering the minimum requirements of the EAA in proportion to the lowered protein concentration or equalizing the dietary amino nitrogen content by use of glutamic acid would prevent the reduction in performance. Chicks were fed the experimental diets from 7 to 21 days of age, and body weight gain, feed consumption, and feed efficiency were determined. In the first experiment, the chicks were fed diets with 23, 20, or 17% CP with minimum EAA set at 100% of the 1984 National Research Council (NRC) suggested requirements. Other groups were fed the 20% CP diet with EAA set at 93.5% or the 17% CP diet set at either 93.5 or 87.5% of the NRC requirements. In the second experiment, the 23% and 17% CP diets were fed, and glutamic acid was added at 3, 6, or 9% to provide the amino nitrogen equivalent of 23% protein with the minimum EAA set at 100% of 1984 NRC requirements. In the first experiment, body weight gain and feed efficiency, but not feed intake, were depressed by lowering CP content. Reducing the minimum EAA requirements in proportion to the reduction in CP failed to correct the difference in performance between the high and low CP diets. In Experiment 2, body weight gain and feed intake were reduced as intact CP decreased and glutamic acid increased, but feed efficiency was unaffected.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids, Essential↗